📘 Chapter 2 – Exploring Substances: Acidic, Basic, Neutral

🔹 Part 3: Neutralisation (Q51–Q75)

Q51. Neutralisation is the reaction between:

A) Two acids
B) Two bases
C) An acid and a base
D) Acid and salt

✅ Answer: C) An acid and a base

Explanation:

• Two acids or two bases do not neutralise each other.
• Acid + base → Salt + water (Correct).
• Acid + salt is not a neutralisation reaction.

Q52. The products of a neutralisation reaction are:

A) Acid and base
B) Salt and water
C) Only salt
D) Only water

✅ Answer: B) Salt and water

Explanation:
Acid + Base → Salt + Water (Correct).

Q53. Which of the following is a neutralisation reaction?

A) HCl + NaOH → NaCl + H₂O
B) H₂SO₄ + Cu → CuSO₄ + H₂
C) CaCO₃ + HCl → CaCl₂ + CO₂ + H₂O
D) NaOH + NaCl → No reaction

✅ Answer: A) HCl + NaOH → NaCl + H₂O

Q54. What helps in curing indigestion caused by excess acid in the stomach?

A) Strong acid
B) Antacids
C) Water
D) More HCl

✅ Answer: B) Antacids

Explanation:
Antacids are mild bases that neutralise extra HCl (Correct).

Q55. The reaction between acid and base is:

A) Exothermic
B) Endothermic
C) Both
D) Neither

✅ Answer: A) Exothermic

Explanation:
Heat is released during neutralisation (Correct).

Q56. Which of these is an example of neutralisation in daily life?

A) Ant sting treated with baking soda
B) Vinegar used in food
C) Soap making
D) Rusting of iron

✅ Answer: A) Ant sting treated with baking soda

Explanation:

• Ant sting → Contains formic acid.
• Baking soda (base) neutralises it (Correct).

Q57. Which base is present in milk of magnesia used for acidity relief?

A) Sodium hydroxide
B) Potassium hydroxide
C) Magnesium hydroxide
D) Calcium hydroxide

✅ Answer: C) Magnesium hydroxide

Q58. Which of the following is NOT a neutralisation example?

A) Soil treated with lime
B) Antacids for acidity
C) Vinegar used for sour taste
D) Ant sting treated with baking soda

✅ Answer: C) Vinegar used for sour taste

Q59. Neutralisation reaction is used in agriculture to:

A) Make food tasty
B) Reduce soil acidity
C) Increase soil acidity
D) Add more salts

✅ Answer: B) Reduce soil acidity

Explanation:
Lime (Ca(OH)₂) is added to neutralise acidic soil (Correct).

Q60. Which of the following is correct?

A) Neutralisation produces only heat
B) Neutralisation produces salt and water
C) Neutralisation produces hydrogen gas
D) Neutralisation produces acid

✅ Answer: B) Neutralisation produces salt and water

Q61. Factory waste containing acids can be neutralised by:

A) Adding water
B) Adding bases
C) Adding more acid
D) Adding salts

✅ Answer: B) Adding bases

Q62. What is the pH of a neutral solution?

A) 0
B) 7
C) 14
D) 1

✅ Answer: B) 7

Q63. Which of the following is an antacid?

A) HCl
B) NaOH
C) Mg(OH)₂
D) HNO₃

✅ Answer: C) Mg(OH)₂

Q64. Burning sensation of ant bite is caused by:

A) Sulphuric acid
B) Formic acid
C) Lactic acid
D) Acetic acid

✅ Answer: B) Formic acid

Q65. The burning sensation of an ant sting can be neutralised by:

A) Vinegar
B) Baking soda
C) More acid
D) Salt

✅ Answer: B) Baking soda

Q66. Which is used to treat acidic soil in agriculture?

A) NaOH
B) Ca(OH)₂
C) HCl
D) Vinegar

✅ Answer: B) Ca(OH)₂ (Lime)

Q67. The neutralisation reaction is useful in:

A) Agriculture
B) Medicine
C) Waste treatment
D) All of these

✅ Answer: D) All of these

Q68. Which statement is correct about neutralisation?

A) It decreases temperature
B) It always releases heat
C) It produces hydrogen gas
D) It produces carbon dioxide

✅ Answer: B) It always releases heat

Q69. Which of the following pairs is an acid and a base?

A) HCl and NaOH
B) HCl and H₂SO₄
C) NaOH and KOH
D) NaCl and H₂O

✅ Answer: A) HCl and NaOH

Q70. Which of the following is formed when acid reacts with base?

A) Only salt
B) Only water
C) Salt and water
D) Acid

✅ Answer: C) Salt and water

Q71. Indigestion is caused by:

A) Excess base in stomach
B) Excess acid in stomach
C) Lack of enzymes
D) Only water

✅ Answer: B) Excess acid in stomach

Q72. Which of these reactions is exothermic neutralisation?

A) HCl + NaOH → NaCl + H₂O
B) HCl + Na → NaCl + H₂
C) HCl + CaCO₃ → CaCl₂ + CO₂ + H₂O
D) NaOH + Na → No reaction

✅ Answer: A) HCl + NaOH → NaCl + H₂O

Q73. Which neutralisation reaction is used in treating wasp sting?

A) Vinegar applied
B) Baking soda applied
C) Soap applied
D) Water applied

✅ Answer: A) Vinegar applied

Explanation:

• Wasp sting → Alkaline poison.
• Vinegar (acid) neutralises it (Correct).

Q74. Which of the following is NOT an application of neutralisation?

A) Antacids for acidity
B) Soil treatment
C) Wasp sting treatment
D) Rusting of iron

✅ Answer: D) Rusting of iron

Q75. Neutralisation is important because:

A) It helps in cleaning clothes
B) It helps to balance acids and bases in daily life
C) It helps in photosynthesis
D) It helps in making oxygen

✅ Answer: B) It helps to balance acids and bases in daily life

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